Equalizing basin

An equalizing basin (German: Ausgleichsbecken) or equalizing reservoir regulates the flow of water below an intermittently operated hydropower station or peaking power plant. This could be a part-load power station (Teillast-Durchfluss-Kraftwerk) or a storage power station. Also called a balancing reservoir.

Function

The hydropower station sited above the basin works only a few hours a day. Often it is only used to generate peak current electricity. During hours of low current demand, the power station switches off in order to save the water available in the headstream for the valuable peak power times.

Without some form of equalization, however, the tailwaters would run dry when the turbines shut down. This would result in extremely low levels of water, causing serious problems for the plants and animals that live in and around the stream or river.

In general, therefore, the power station operator today is required to regulate the flow in order to ensure a specified minimum level of water flow into the tailwaters. During periods when the turbines are running (peak current generation) the equalizing basin fills up; during periods when the turbines are shut down, the basin drains gradually.

Basin

Basin is another term for sink or bowl.

Basin may also refer to:

Geology and landforms

Basin may also refer to some types of geological depressions:

Dock (maritime)

A dock (from Dutch dok) is either the area of water between or next to a human-made structure or group of structures involved in the handling of boats or ships, usually on or close to a shore, or the structures themselves. The exact meaning varies among different variants of the English language. "Dock" may also refer to a dockyard or shipyard where the loading, unloading, building, or repairing of ships occurs.

History

The earliest known docks were those discovered in Wadi al-Jarf, an ancient Egyptian harbor dating from 2500 BCE located on the Red Sea coast. Archaeologists also discovered anchors and storage jars near the site. A dock from Lothal in India dates from 2400 BCE and was located away from the main current to avoid deposition of silt. Modern oceanographers have observed that the Harappans must have possessed great knowledge relating to tides in order to build such a dock on the ever-shifting course of the Sabarmati, as well as exemplary hydrography and maritime engineering. This was the earliest known dock found in the world, equipped to berth and service ships. It is speculated that Lothal engineers studied tidal movements, and their effects on brick-built structures, since the walls are of kiln-burnt bricks. This knowledge also enabled them to select Lothal's location in the first place, as the Gulf of Khambhat has the highest tidal amplitude and ships can be sluiced through flow tides in the river estuary. The engineers built a trapezoidal structure, with north-south arms of average 21.8 metres (71.5 ft), and east-west arms of 37 metres (121 ft).

Basin (chanson de geste)

Basin is a chanson de geste about Charlemagne's childhood. While the Old French epic poem has been lost, the story has come down to us via a 13th-century Norse prose version in the Karlamagnús saga.

Plot

At the death of his father, an angel warns the young Charlemagne to take to the Ardennes and join up with the notorious thief Basin. During their adventures, Charlemagne learns of a plot to kill him and, in the end, the traitors are discovered, Charlemagne is crowned and Basin the thief is rewarded.

Historical sources

The traitors in the story (Rainfroi and Helpri) are most likely based on Chilperic and Ragenfrid who were defeated by Charles Martel in 717 CE. It is unknown if the author was acquainted with an 11th-century version of these events called Passio Agilolfi.

Influence

The names of the traitors in Basin were passed on to two other chansons de geste about Charlemagne's youth: Mainet and Berthe aus grans piés.

References